.BFSAR File Extension
What is a BFSAR file?
A BFSAR files is an archive that contains multiple .BFWAV audio files used by the Mario Kart 8 (MK8) game for Nintendo Wii U and Switch. It stores sound effects that are played during races and when navigating game menus. BFSTM files replaced .BRSTM and .BCSTM files, which are commonly used by Wii and 3DS games.
You most likely will only encounter BFSAR files if you are looking to modify the sound effects that are used during MK8U gameplay. The file is often modified by Mario Kart 8 for Wii U (MK8U) gamers.
BFSAR files are not meant to be manually opened. They are referenced by the game on the Wii U or Switch game console. However, gamers that want to modify the sound effects stored in BFSAR archives often use the MK8 BFSAR Editor.